Subsurface pesticide injection and fluid extraction system

ABSTRACT

A subsurface pesticide injection system for use in combination with a structure having a footing formed in a base soil, a stem wall formed on the footing and defining a perimeter of the structure, a fill material disposed on the base soil within the perimeter of the stem wall, and a concrete slab formed on the fill material is provided. The concrete slab has openings extending therethrough. The subsurface pesticide injection and fluid extraction system comprising includes a tubular conduit disposed adjacent the foundation of the structure. The tubular conduit has a sidewall and a plurality of tortuous pores extending through the sidewall of the tubular conduit. A connector member is attached to one of the first and second ends of the tubular conduit and detachably connectable to a source of pressurized pesticide such that pesticide may be selectively injected into the fill material in an injection mode to form a chemical barrier against the infestation of pests into the structure through the openings of the concrete slab.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 10/209,566, filedJul. 30, 2002, now U.S. Pat. No. 6,564,504 which is a continuation ofU.S. Ser. No. 09/594,952, filed Jun. 15, 2000, now U.S. Pat. No.6,446,383, which is a continuation-in-part of U.S. Ser. No. 09/109,653,filed Jul. 2, 1998, now abandoned, the content of each hereby expresslyincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to insect control systems andvapor exhaust systems for structures, and more particularly, but not byway of limitation, to an improved system for both selectively injectingpesticide beneath a structure and extracting fluids, such as water andharmful vapors from beneath the structure.

2. Brief Description of the Related Art

Numerous systems have been proposed for protecting buildings and homesfrom damage caused by pests, such as subterranean termites, which can doconsiderable structural and cosmetic damage over time. A common practicefor treating infestation of pests into a structure is to pretreat theground under the structure with pesticide chemicals during theconstruction process. This is done by applying a substantial quantity ofpesticides, such as termiticide, on the ground under the proposedstructure before the slab is poured in an attempt to create a chemicalbarrier that will keep the insects from entering the structure.

The problem with this method of treatment is the amount of pesticiderequired to be used can be harmful to occupants of the structure as wellas harmful to the ground water. Furthermore, even though a large amountof pesticide is applied to the ground, the resulting chemical barriernevertheless becomes ineffective over time as the chemicals break down.

With these problems in mind, other methods have been developed for theperiodic injection of pesticide beneath structures. One particularmethod involves the drilling of holes in and around the slab for theinjection of pesticide. This method has many drawbacks which includeaffecting the integrity of the slab, the mess of drilling through theslab, convenience of having to clear a path around the structure topermit access for the drilling, the need for the holes to be plugged,and the residual odor of the pesticide that escapes during the injectionprocess. In addition, this process must be periodically repeated duringthe lifetime of the structure.

Considerable efforts have been made to alleviate the problems of postconstruction periodic injection of pesticides beneath the structure byplacing a injection system beneath the structure during the constructionprocess. Many of these systems involve placing a network of poroustubing beneath the structure. The problem encountered in these systemshowever is that the holes provided in the tubing have a fixed diameterand thus are susceptible to clogging. That is, because the preference toplace the network of tubing within the fill material positioned underthe slab, the fill material often obstructs or clogs the holes. Theholes can also get clogged by dead insects and other pests that mayenter the holes in the tubing over the course of the lifetime of thesystem. When the holes become clogged or obstructed, they fail todeliver pesticide to the surrounding location, thereby creating a gap inthe chemical barrier which can be exploited by pests.

Other injection network systems with fixed holes have attempted toprevent hole obstruction elaborate systems or by varying constructionprocedures. For example, systems have been developed where the holes aresheltered with wick-like membranes, soil screens, shower-type sprinklerheads, and sponges. Other systems attempt to keep the holes from beingobstructed by surrounding the holes with specialized fill materialsapplied during the construction process. Each of these types of systemsis complex and increases installation costs.

Another problem of concern in many regions of the country isaccumulation of moisture and/or harmful gases, such as radon, beneathhomes and other structures. The accumulation of water beneath a floorslab can be a substantial problem, particularly where the water table ishigh or rainfall is plentiful. The accumulation of water beneath theslab of a structure can result in the seepage of water through thefoundation and into the structure. In addition, the water is a breedingground for microorganisms, such as mold and mildew, and may also causethe foundation to erode.

Radon is produced by the gradual decay of solid radioactive elements inthe soil. While geographic regions that contain large concentrations ofsolid radioactive elements in the soil, the mere release of the gas evenin these areas is not a concern in that the uninterrupted movement ofradon into the atmosphere is generally at such a slow rate that littleor no health hazard is posed.

The concern has risen in recent years due to the discovery of largeconcentrations of radon gas that had accumulated in dwellings. It becameapparent that it was not the rate at which radon gas was given off bythe soil, but the failure of dwellings to allow radon and othercontaminants to continue on into the atmosphere. This has been caused bythe effort of builders to make homes more energy efficient by thermallysealing the structures as tight as possible.

One factor in the degree of gas accumulation is the construction of thebuilding itself and more specifically the construction of the supportsystem in contact with the ground. That is, more and more homes arebeing built upon what is called a slab foundation. The effect of thistype of foundation is to act as a cap to contain gases from the soil,allowing them to escape only when they find their way up into the houseby the way of the cracks and plumbing openings formed in the slab.

Numerous subsurface ventilation systems have been proposed. However,like the prior art pesticide systems discussed above, these ventilationsystems are susceptible to clogging, are relatively complex, andexpensive to install. In addition, the prior art ventilation systems arenot adapted to serve a dual purpose of periodically deliveringpesticides beneath the structure.

To this end, a need exists for a subsurface pesticide injection andfluid extraction system which is simple in design, inexpensive toinstall, and easy to operate and maintain. It is to such a system thatthe present invention is directed.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view of a foundation of a dwelling with asubsurface pesticide injection and fluid extraction system constructedin accordance with the present invention installed under the foundation.

FIG. 2 is a cross-sectional view of a portion of the foundationillustrating the subsurface pesticide injection and fluid extractionsystem of FIG. 1 installed under the foundation.

FIG. 3 is a perspective view of an elastomeric conduit used with thesubsurface pesticide injection and fluid extraction system of thepresent invention.

FIG. 4 is a perspective view of the elastomeric conduit of FIG. 3 shownin an expanded condition for releasing fluid in accordance with thepresent invention.

FIG. 4A is a perspective view of the elastomeric conduit of FIG. 3 shownin a contracted condition for drawing fluid in accordance with thepresent invention.

FIG. 5 is a partially cutaway, perspective view of a service panel ofthe subsurface pesticide injection and fluid extraction system of thepresent invention.

FIG. 6A is a perspective view of the tubular conduit of FIG. 6 shown inan expanded condition for injecting fluid in accordance with the presentinvention.

FIG. 7 is a perspective view of another embodiment of a service panel ofthe subsurface pesticide injection and fluid extraction system of thepresent invention.

FIG. 8 is a perspective view of yet another embodiment of a servicepanel of the subsurface pesticide injection and fluid extraction systemof the present invention.

FIG. 9 is a side elevational view of a hose adaptor for permitting theinjection of hot water beneath the slab.

FIG. 10 is a side elevational view of a pesticide injection assembly forpermitting the injection of pesticide beneath the slab.

FIG. 11 is a side elevational view illustrating a vacuum pump forpermitting the extraction of fluids from beneath the slab.

FIG. 12 is a cross-sectional view of a portion of the foundationillustrating alternative embodiments of the subsurface pesticideinjection and fluid extraction system of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings and more particularly to FIGS. 1 and 2, asubsurface pesticide injection and fluid extraction system 10constructed in accordance with the present invention is shown installedbeneath a foundation 12 of a structure. The foundation 12 has a footing14 formed in a base soil 16 (FIG. 2). The footing 14 provides a supportsurface for a brick exterior 17 (FIG. 2) and a stem wall 18 whichgenerally defines a perimeter of the structure. A fill material 20, suchas sand or gravel, is disposed on the base soil 16 within the perimeterof the stem wall 18, and a concrete slab 22 is formed on the fillmaterial 20. A plurality of plumbing pipes 24, which run through thefill material 20, protrude up through the concrete slab 22.

Upon curing of the concrete slab 22, openings or cracks typically formbetween the stem wall 18 and concrete slab 22, as well as between theplumbing pipes 24 and the concrete slab 22, such as openings 25. Theseopenings and cracks provide an entry point into the structure for pestsand fluids, including water and vapors, such as radon gas. Consequently,the area near the perimeter of the concrete slab 22 and the areaadjacent where the plumbing pipes 24 protrude up through the concreteslab 22 require periodic attention to prevent pest infestation andaccumulation of harmful fluids in the structure.

The subsurface pesticide injection and fluid extraction system 10includes one or more circuits of tubular conduit 26 positioned under thefoundation of the structure and a connector assembly 28 which permits asource of pressurized pesticide to be connected to the tubular conduits.As such, pesticide may be selectively injected into the fill material inan injection mode to form a chemical barrier against the infestation ofpests into the structure through the openings of the concrete slab. Inaddition, a vacuum source may be connected to the tubular conduits sothat fluids may be selectively extracted from the fill material in anextraction mode to reduce the passage of fluids into the structurethrough the openings of the concrete slab.

FIGS. 1 and 2 illustrate the subsurface pesticide injection and fluidextraction system 10 having a circuit 30 which is positioned adjacent tothe perimeter of the concrete slab 22 and a circuit 32 which ispositioned to loop in close proximity to the upward extending plumbingpipes 24. The system 10 is also illustrated having a circuit 33extending around the perimeter of the structure on the exterior side ofthe footing 14 and a circuit 35 positioned in a space 36 formed betweenthe brick exterior 17 and the stem wall 18. While the circuits 33 and 35can be utilized to deliver pesticide and extract fluids in a manner tobe discussed below, the circuits 33 and 35 are primarily provided fordelivering pesticide.

As illustrated in FIG. 2, the tubular conduit 26 of the circuit 30 canbe secured in the fill material 20 with a hook 39 to prevent the tubularconduit 26 from floating into the concrete slab 22 when the concreteslab 22 is being poured.

Referring now FIGS. 3, 4 and 4A, the porous conduit 26 is generallytubular and has a sidewall 34, a first end 37, a second end 38, and aplurality of pores 40 extending through the sidewall 34 from the firstend 37 to the second end 38. The tubular conduit 26 has a substantiallycircular cross-sectional configuration and is constructed of anelastomeric material, such as rubber, neoprene, or plastic. As a result,upon applying a positive internal pressure to the tubular conduit 26,the sidewall 34 expands slightly thereby causing the pores 40 of thetubular conduit 26 to open (FIG. 4) and permit the release of fluid fromthe tubular conduit 26 into the fill material 20 in an injection mode.Upon applying a negative internal pressure to the internal conduit 26,the sidewall 34 collapses slightly thereby causing the pores of thetubular conduit 26 to open inwardly (FIG. 4A) and permit the drawing offluid from the fill material 20 into the tubular conduit 26 in anextraction mode. Finally, upon removal of the positive and negative andinternal pressures from the tubular conduit 26, the pores 40 are causedto close (FIG. 3) so that the pores 40 remain substantially clog freewhile the tubular conduit 26 maintains a substantially circularcross-sectional configuration under the load of the fill material 20.

As illustrated in FIG. 5, the connector assembly 28 includes an accessbox 42 having a plurality of access ports or female connector members 44(only one of the access ports being designated in FIG. 5) and aplurality of nonporous tubular conduits 46 (only one of the nonporoustubular conduits being designated in FIG. 5) for establishing fluidcommunication between the access ports 44 and the porous conduits 26.The nonporous tubular conduits 46 are preferably constructed of arelatively flexible material, such as polyethylene. The access box 42includes an access port 44 for each end of the tubular conduit 26 foreach circuit 30, 32, and 33, and 35. Each nonporous tubular conduit 46is disposed in one end of a corresponding porous tubular conduit 26 andthe porous tubular conduit 26 is secured thereto with a suitable device,such as a hose clamp (not shown).

Each access port 44 is adapted to receive a source of pressurizedpesticide whereby the pesticide may be selectively injected into thefill material 20 in a injection mode via the porous conduits 26 to forma chemical barrier against the infestation of pests into the structurethrough the openings 25 of the concrete slab 22. A source of pressurizedpesticide may be attached to each of the access ports 44 or to only oneof the access ports 44. If the source of pressurized pesticide isconnected to only one of the access ports 44, the other access port 44is plugged with a cap (not shown).

In a like manner, each access port 44 is also adapted to be detachablyconnected to a vacuum source whereby fluids may be selectively extractedfrom the fill material 20 in an extraction mode to reduce the passage offluids into the structure through the openings 25 of the concrete slab22.

The access ports 44 are illustrated as being configured for threadedattachment with the source of pressurized pesticide and the vacuumsource. The access box 42 can be located in any convenient location suchas on a wall of a garage, in a utility closet, or on an exterior wall ofthe structure.

FIGS. 6 and 6A illustrate another embodiment of a tubular conduit 26 awhich can be used in the system 10 of the present invention forinjecting pesticide into the fill material 20 and the base soil 16 andfor extracting fluids from the fill material 20. The tubular conduit 26a is formed of particles of vulcanized rubber dispersed in a binderresin such that tortuous pores or channels are formed in the side wall.Examples of suitable conduits are disclosed in U.S. Pat. No. 4,003,408,assigned to George C. Ballas, trustee, and U.S. Pat. No. 5,474,398,assigned to Aquapore Moisture Systems, Inc. of Phoenix, Ariz., both ofwhich are hereby expressly incorporated herein.

Like the tubular conduit 26, the tubular conduit 26 a is generallytubular and has a side wall 34 a, a first end 37 a, a second end 38 a,and a plurality of small tortuous pores or channels 40 a extendingthrough the side wall 34 a. Further, the sidewall 34 a has a thicknesssufficient to give the tubular conduit 26 a structural integrity toprevent collapse of the tubular conduit 26 a due to soil loadingpressures. The sidewall 34 a is also of such thickness so that thetubular conduit 26 a maintains a high degree of flexibility along itlength to facilitate installation.

The tubular conduit 26 a has a substantially circular cross-sectionalconfiguration and is constructed of an elastomeric material such thatupon applying a positive internal pressure to the tubular conduit 26 aby the injection of the pressurized pesticide into the tubular conduit26 a, the sidewall 34 a expands slightly causing the tortuous pores 40 aof the tubular conduit 26 a to open and permit pesticide to drip throughthe tortuous pores 40 a into the fill material 20 in the injection modewhile the tubular conduit 26 a maintains its substantially circularcross-sectional configuration. Upon applying a negative internalpressure to the tubular conduit 26 a, the sidewall 34 a is caused tocollapse slightly causing the tortuous pores 40 a of the tubular conduit26 a to open inwardly and permit fluids to be drawn through the tortuouspores 40 a from the fill material 20 into the tubular conduit 26 a inthe extraction mode while the tortuous pores 40 a remain substantiallyclog free and the tubular conduit 26 a maintains its substantiallycircular cross-sectional configuration. Finally, upon removal of thepositive and negative internal pressures the tortuous pores 40 a arecaused to close so that the tortuous pores 40 a remain substantiallyclog free while the tubular conduit 26 a maintains its substantiallycircular cross-sectional configuration.

FIG. 7 illustrates another embodiment of a connector assembly 50 shownmounted to an exterior wall 52 of a structure. Like the connectorassembly 28, the connector assembly 50 includes a plurality of nonporoustubular conduits 53. Each nonporous tubular conduit 53 of the connectorassembly 50 is provided with a male connector member 54 rather than afemale connector member as with the connector assembly 28. The maleconnector members 54 are shown to extend from the wall 52 and to besupported by a support plate 56.

Each male connector 54 is adapted to receive a source of pressurizedpesticide whereby the pesticide may be selectively injected into thefill material 20 in a injection mode via the porous conduits 26 to forma chemical barrier against the infestation of pests into the structurethrough the openings 25 of the concrete slab 22. A source of pressurizedpesticide may be attached to each of the male connector members 54,whereby pesticide is simultaneously injected into both ends of theporous conduit 26, or to only one of the access ports 44. If the sourceof pressurized pesticide is connected to only one of the access ports44, the other access port 44 is preferably plugged with a cap 58 orother suitable device.

In a like manner, each male connector 54 is also adapted to bedetachably connected to a vacuum source whereby fluids may beselectively extracted from the fill material 20 in an extraction mode toreduce the passage of fluids into the structure through the openings 25of the concrete slab 22.

Like the access box 42 of the connector assembly 28, the male connectormembers 54 can also be located in any other convenient location such ason a wall of a garage or in a utility closet.

FIG. 8 illustrates a connector assembly 50 a which is similar to theconnector assembly 50 described above with the exception that aY-connector 59 is attached to the ends of each corresponding nonporoustubular conduit 53 to provide a single point of injection and evacuationfor each circuit. Injection of pesticide and evacuation of fluids ismade via the male connectors 54. Use of the Y-connector 59 permitspesticide to be simultaneously injected through both ends of the porousconduit 26 in the injection mode and fluids to be simultaneouslywithdrawn from both ends of the porous conduit 26 in the evacuationmode. Particularly with respect to the injection mode, it has been foundthat the amount of time required to inject a selected volume ofpesticide into the fill material 20 by simultaneously injecting thepesticide through both ends of the porous conduit is decreased more than60%. For example, the amount of time to inject a pesticide into a fillmaterial using a 500 foot length of porous conduit was decreased fromapproximately eight minutes when injecting the pesticide into only oneend of the porous conduit to approximately three minutes whensimultaneously injecting pesticide into both ends of the 500 foot lengthof porous conduit.

Referring now to FIG. 9, an adapter hose 60 suitable for use ininjecting a source of pressurized pesticide 62 in the injection mode isshown. The pesticide is illustrated in FIG. 9 as being hot water whichis known to control certain pests. A preferred temperature range for thewater is from about 90 degrees Fahrenheit to about 180 degreesFahrenheit. However, water temperatures as low as about 60 degrees maybe effective in controlling certain types of pests.

One end of the adapter hose 60 is provided with a female connectormember 64 which is adapted to be attached to and detached from the maleconnector member 54 quickly and easily. The other end of the adapterhose 60 is provided with a connector member 66 which is adapted to beconnected to the source of pressurized pesticide 62.

FIG. 10 illustrates a pesticide injection device 70 suitable for use indelivering a liquid pesticide, such as a termiticide, in the injectionmode. The pesticide injection device 70 includes a reservoir 72 forholding an amount of liquid pesticide and a siphoning device 74 capableof mixing a metered amount of the liquid pesticide with a selectedvolume of pressurized fluid. The siphoning device 74 is provided with afemale connector member 76 which is adapted to be attached to anddetached from the male connector member 54 quickly and easily. The otherend of the siphoning device 74 is provided with a connector member 78which is adapted to be connected to a source of pressurized fluid 80.

The amount of pressure required to effectively inject the pesticide intothe fill material 20 and into the base soil 16 will vary depending onthe density of the fill material 20 and the base soil 16. However, apressure range of from about 2 psi to about 80 psi is generallysuitable.

FIG. 11 illustrates a pump 82 suitable for creating a vacuum in theporous tubular conduits 26 and 26 a whereby fluid may be selectivelyextracted from beneath the foundation 12 of the structure in theextraction mode to reduce the passage of fluids into the structure. Thepump 82 has an intake line 84 with a female connector member 86 which isadapted to be attached to and detached from the male connector member 54quickly and easily. The pump 82 also includes an exhaust line 88 whichis adapted to be connected to an extension hose 90 for exhausting thefluids to the exterior of the structure.

FIG. 12 illustrates alternative locations for placement of the tubularconduit, such as tubular conduit 26. In one instance, it may bedesirable to place the tubular conduit 26 in the lower portion of thefill material 20, as opposed to the upper portion of the fill material20. More specifically, the tubular conduit 26 can be positioned alongthe lower end of an insulation material 92 fixed to the interior side ofthe stem wall 18 to prevent pests from migrating between the insulationmaterial 92 and the stem wall 18. In another instance, it may bedesirable to place the tubular conduit 26 at the perimeter of the stemwall 18 such that the tubular conduit 26 is positioned in the concreteslab 22 so as to be in the path of where cracks are likely to formbetween the stem wall 18 and the concrete slab 22. Prior to forming theconcrete slab 22, the tubular conduit may be secured to the stem wall 18with a suitable adhesive.

From the above description it is clear that the present invention iswell adapted to carry out the objects and to attain the advantagesmentioned herein as well as those inherent in the invention. Whilepresently preferred embodiments of the invention have been described forpurposes of this disclosure, it will be understood that numerous changesmay be made which will readily suggest themselves to those skilled inthe art and which are accomplished within the spirit of the inventiondisclosed and as defined in the appended claims.

What is claimed is:
 1. A subsurface pesticide injection system incombination with a structure having a foundation, the subsurfacepesticide injection system comprising: a tubular conduit disposedadjacent the foundation of the structure, the tubular conduit having asidewall and a plurality of tortuous pores extending through thesidewall of the tubular conduit, the tubular conduit connectable to asource of pesticide to permit pesticide to be selectively introducedinto the tubular conduit, the tubular conduit constructed of anelastomeric material such that the introduction of pesticide into thetubular conduit causes the tortuous pores of the tubular conduit to openand release pesticide from the tubular conduit adjacent the foundationof the structure.
 2. A subsurface pesticide injection system incombination with a structure having a foundation which defines aperimeter of the structure, the subsurface pesticide injection systemcomprising: a tubular conduit disposed on an interior side of thefoundation of the structure, the tubular conduit having a sidewall and aplurality of tortuous pores extending through the sidewall of thetubular conduit, the tubular conduit connectable to a source ofpesticide to permit pesticide to be selectively introduced into thetubular conduit, the tubular conduit constructed of an elastomericmaterial such that the introduction of pesticide into the tubularconduit causes the tortuous pores of the tubular conduit to open andrelease pesticide from the tubular conduit on the interior side of thefoundation of the structure.
 3. A subsurface pesticide injection systemin combination with a structure having a foundation formed in a basesoil, the subsurface pesticide injection system comprising: a tubularconduit disposed within the base soil adjacent an exterior side of thefoundation, the tubular conduit having a sidewall and a plurality oftortuous pores extending through the sidewall of the tubular conduit,the tubular conduit connectable to a source of pesticide to permitpesticide to be selectively introduced into the tubular conduit, thetubular conduit constructed of an elastomeric material such that theintroduction of pesticide into the tubular conduit causes the tortuouspores of the tubular conduit to open and release pesticide from thetubular conduit into the base soil on the exterior side of thefoundation of the structure.
 4. A pesticide injection system incombination with a structure, the structure having an exterior facing,the pesticide injection system comprising: a tubular conduit disposedadjacent an interior side of the exterior facing of the structure, thetubular conduit having a sidewall and a plurality of tortuous poresextending through the sidewall of the tubular conduit, the tubularconduit connectable to a source of pesticide to permit pesticide to beselectively introduced into the tubular conduit, the tubular conduitconstructed of an elastomeric material such that the introduction ofpesticide into the tubular conduit causes the tortuous pores of thetubular conduit to open and release pesticide from the tubular conduitadjacent the interior side of the exterior facing of the structure.